Surgical devices for access to surgical sites

ABSTRACT

Access devices including access ports and retractors, which enhance the working area and access to a surgical site. The access port includes a tubular body with at least one sidewall defining an interior path along the length of the tubular body. The sidewall includes a rigid portion and a flexible portion. The flexible portion is able to stretch or deform, for example, to accommodate an angled trajectory of a surgical implement. A surgical access device for retracting tissue includes a plurality of retractor blades. The outer surface of the retractor blades form a substantially circular cross-sectional configuration with a plurality of spiral ridges projecting therefrom such that advancement of the retractor into the surgical site may be improved.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application of U.S. patentapplication Ser. No. 14/212,903 filed on Mar. 14, 2014 (published asU.S. Patent Publication No. 2015-0257746), which is hereby incorporatedby reference in its entirety herein.

FIELD OF THE INVENTION

The present disclosure generally relates to devices used in surgery.More particularly, the surgical devices include instruments and toolsfor providing access to and retraction of surgical sites.

BACKGROUND OF THE INVENTION

In surgical procedures, access ports and retractors are often used toprovide access to a surgical site. In minimally invasive surgical (MIS)procedures, for example, in spinal surgery, access ports may be used toprovide direct and unobstructed access to the surgical site. By way ofexample, one or more screws may be delivered through the access port tosecure a spinal fixation device. The access port is typically rigid toaid insertion of the screws, allow for fixation and attachment to atable arm, to provide for soft tissue distraction, or other similarfunctions. The rigid access ports, however, can restrict or prohibitinsertion of the screws or other surgical devices or instruments if theinsertion path extends beyond the working area of the rigid access port.Thus, rigid access ports may not be able to accommodate an angledtrajectory and/or a long length of the screws, for example.

Retractors or retractor systems are also used in a variety of differentsurgical procedures to provide an opening through which an operator mayaccess the surgical site. In spinal surgeries, for example, a retractormay be used to provide the surgeon with improved access to the patient'sspine. The opening created by the retractor may, for example, enable thesurgeon to insert surgical instruments, devices, and the like into thebody and improve visualization of the surgical site. The retractor mayinclude blades, which may be inserted into an incision and thenretracted to displace the tissue surrounding the incision down to thesurgical site. Typical retractors, however, may be difficult to advanceor insert into the soft tissue or may damage the surrounding tissue.

SUMMARY OF THE INVENTION

To meet these and other needs, access devices are provided, whichimprove the working area and access to the surgical site. In particular,access ports are provided with flexible areas designed to accommodateangled trajectories and long lengths for surgical devices andimplements. The retractors are provided with retractor blades havingspecially designed outer surfaces configured to improve penetration andadvancement of the retractor into the surgical site.

According to one embodiment, a surgical access device for providingaccess to a patient during surgery includes a tubular body having afirst end defining a first opening configured for receiving a surgicalimplement, a second end defining a second opening configured foraccessing the patient, a length extending from the first end to thesecond end, and at least one sidewall defining an interior path alongthe length of the tubular body. The at least one sidewall includes arigid portion and a flexible portion. The flexible portion extends alongat least a portion of the length of the tubular body. The flexibleportion may be configured to stretch or deform to accommodate an angledtrajectory of the surgical implement.

The flexible portion may be situated along the length of the tubularbody and can replace at least a portion of a traditional rigid sidewall.The flexible portion may be configured to expand radially and/or tostretch laterally. For example, the flexible portion may extend from thefirst end or the second end to a distance along the length of thetubular body. For example, the flexible portion may extend to greaterthan 50% of the length of the tubular body. The flexible portion mayencompass a portion of the outer perimeter or the entire outer perimeteralong a given length of the tubular body. The flexible portion may beformed from a woven biocompatible material, such as a mesh structure,which is flexible in one or more directions.

The rigid portion comprises the remainder of the tubular body notcontaining the flexible portion. The rigid portion may include anannular collar, for example, positioned at the first end or the secondend of the tubular body. The rigid portion may extend from the first endto the second end along the entire length of the tubular body. Theflexible portion and the rigid portion may bifurcate at least a portionof the tubular body, for example, parallel to or perpendicular to alongitudinal axis of the tubular body.

The tubular body may have any suitable cross-sectional configurationdesigned to accommodate the surgical implements on a given angledtrajectory. The tubular body may have a substantially uniform diameteralong a portion of its length or its entire length. The tubular body mayalso include an enlarged portion. The tubular body may have a firstdiameter at the first end and a second diameter at the second end wherethe first and second diameters are not equal. For example, the firstdiameter may be larger than the second diameter or the second diametermay be larger than the first diameter. The tubular body may also have athird diameter positioned between the first and second ends. The thirddiameter may be the same or different (e.g., larger or smaller) from thefirst and second diameters. By way of example, the tubular body may havea shape selected from a bulbous shape, an hourglass shape, a dumbbellshape, a tapered shape, a flared shape, a funnel shape, or the like.

According to another embodiment, a surgical access device for retractingtissue includes a plurality of retractor blades each having a generallyarcuate segment with a distal end, a proximal end, and an outer surface.The retractor blades are radially spaced apart to define a passageextending from the proximal end to the distal end. The retractor bladesmay also define at least one continuous slot between each of theretractor blades. The outer surface of the retractor blades may form asubstantially circular cross-sectional configuration having a pluralityof spiral ridges projecting therefrom. The spiral ridges may beconfigured to allow for rotational insertion of the retractor into thesurgical site (e.g., in a corkscrew manner). After insertion, theretractor blades are configured to pivot away from a center line suchthat the passage is expandable and the tissue is retracted in responseto an applied force.

The retractor blades may be fully threaded such that the spiral ridgesextend from the distal end to the proximal end. In the alternative, theretractor blades may be partially threaded such that the spiral ridgesextend from the distal end to a distance less than the proximal end. Theretractor blades may form a beveled tip at the distal end to enhanceinsertion of the retractor blades into the surgical site.

According to another embodiment, a method of retracting tissue includesinserting a surgical retractor into an incision in a patient's skin byrotating the surgical retractor (e.g., like a corkscrew). After theretractor is appropriately inserted, the blades of the surgicalretractor may be moved away from a center line thereof, therebyenlarging the incision and retracting the tissue.

BRIEF DESCRIPTION OF DRAWING

The invention is best understood from the following detailed descriptionwhen read in connection with the accompanying drawing. It is emphasizedthat, according to common practice, the various features of the drawingare not to scale. On the contrary, the dimensions of the variousfeatures are arbitrarily expanded or reduced for clarity. Included inthe drawing are the following figures:

FIG. 1 depicts two vertebrae with a spacer implanted in theintervertebral disk space between the two vertebrae;

FIG. 2 depicts a traditional rigid access port and the inability toaccess a fixation device at the angle needed for proper attachment;

FIG. 3 provides an embodiment of an access port including a rigidportion and a flexible portion able to accommodate and access thefixation device at an angled trajectory;

FIGS. 4A and 4B show alternative embodiments of access ports havingflexible portions;

FIGS. 5A and 5B also depict alternative embodiment of the access ports;

FIG. 6 shows an embodiment of retractor blades having an outer surfacedesigned to improve access to the surgical site;

FIG. 7 shows one embodiment of a retractor;

FIG. 8 shows an alternative embodiment of the retractor blades; and

FIG. 9 depicts another embodiment of a threaded retractor.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the disclosure are generally directed to access devicesincluding access ports and retractors, which enhance the working areaand access to the surgical site. The access devices have one or morepassageways configured to receive a device, instrument, or othersurgical component. The access devices may serve a number of differentfunctions, including aiding insertion of surgical devices and implements(e.g., implants, screws, and the like), providing for soft tissuedistraction, enhancing penetration and advancement of the access deviceinto the surgical site, allowing for fixation and attachment to a tablearm, and other similar functions. Suitable access devices include, butare not limited to, access ports, cannulas, sleeves, lumens,distractors, retractors, retractor systems, etc. For example, the accessdevice may include access ports provided with flexible areas designed toaccommodate angled trajectories and long lengths for surgical devicesand instruments. The access device may also include retractors providedwith retractor blades having specially designed outer surfacesconfigured to improve rotational advancement of the retractor into thesurgical site.

As used herein and in the claims, the terms “comprising” and “including”are inclusive or open-ended and do not exclude additional unrecitedelements, compositional components, or method steps. Accordingly, theterms “comprising” and “including” encompass the more restrictive terms“consisting essentially of” and “consisting of” It is also noted that,as used in this disclosure and the appended claims, the singular forms“a,” “an” and “the” include plural referents unless the context clearlydictates otherwise. Furthermore, the words “proximal” and “distal” referto directions closer to and further away from a reference point,respectively. For example, an operator (e.g., surgeon, physician, nurse,technician, medical professional, etc.) may insert the medical deviceinto the patient with the tip-end (e.g., the distal end) of the deviceinserted inside a patient's body.

The access devices may be adapted to permit insertion through aminimally invasive procedure or micro-incision. The access devices arealso especially suitable for spinal surgeries and procedures. The accessdevices can be subcutaneously or percutaneously inserted into abiological body of a patient, such as a vertebral body, and used toprovide access to the biological body. The access devices facilitateaccess for other surgical instruments; for example, to remove tissuefrom a vertebra or intervertebral disc, insert fixation devices, such asimplants, rods, plates, fasteners, and the like, inject bone graft,cement, or other types of prosthesis, etc., and secure or attachfixation devices. Thus, the access devices may be used to provide apathway for other medical devices to be inserted into a biological bodyto perform surgical procedures.

Examples of surgical procedures suitable for employing the accessdevices described herein include, but are not limited to, insertion andsecurement of interbody fusion devices, bone anchors, fixation devices,including rods, plates and cables, fasteners (such as screws),artificial disks, hip stems, artificial ligaments, trochars forgastro-intestinal work, or any procedure requiring access to a patient.The access devices may be part of any suitable implant instrument usedto provide access to a particular area of a patient's body. The accessdevices can be used to position any suitable implant, instrument and/orother device in any suitable procedure where guidance of the implant,instrument and/or device is used.

By way of example, the surgical procedure may include a spinal fixation,for example, by implanting one or more fixation devices. Referring nowto the figures in which like reference numbers refer to like elements,FIG. 1 depicts two vertebrae 10 with an implant, such as anintervertebral spacer 12, implanted in the intervertebral disk spacebetween the two vertebrae 10. The spacer 12 may be secured to theadjacent vertebrae 10 using one or more fasteners, such as one or morescrews 14. Depending on the configuration of the implant or spacer 12,the screws 14 may need to be provided at an angle for proper fixation inthe adjacent vertebrae 10.

As shown in FIG. 2, traditional access devices, such as access port 20can be restrictive in that the working area of the access port 20 islimited. The access port 20 may include an opening 22 in communicationwith a limited passageway 24 extending through the device. In the caseof access port 20, the rigidity of the access port 20 restricts orprohibits insertion of the surgical devices in the manner required(e.g., at an angle). As is shown, surgical instrument 30 (e.g., a screwdriver) is unable to access or reach screw 14 at the angle needed tosecure the spacer 12 to the vertebrae 10. Due to the angled trajectoryof the screw 14, the desired insertion path extends beyond the workingarea of the rigid access port 20 (i.e., the screw 14 and surgicalinstrument 30 would need to extend beyond the periphery of the accessport 20). Thus, a rigid access port 20 is not able to accommodate thedesired insertion path. The rigid access port 20 is also not able todeliver devices at the necessary angled trajectory or having a longlength for the surgical device (e.g., screw 14) and/or the surgicalinstrument 30.

According to one embodiment, a surgical access device for providingaccess to a patient during surgery includes at least one flexibleportion designed to provide an adaptable and adjustable working area.Referring now to FIGS. 3-5B, embodiments of minimally invasive accessports 100 are illustrated. The access ports 100 each include a tubularbody 102 having a first end 110 defining a first opening 112 configuredfor receiving a surgical implement, a second end 120 defining a secondopening 122 configured for accessing the patient, a length L extendingfrom the first end 110 to the second end 120, and at least one sidewall104 defining an interior path 106 along the length L of the tubular body102. The sidewall 104 includes a rigid portion 130 and a flexibleportion 140.

The access port 100 can be any suitable device defining a port forproviding access to a surgical site. The access port 100 may includesingle access or multiple access points to the surgical area. Forexample, the tubular body 102 may define a channel or interior path 106therethrough including a straight, curved, or any suitable shapedtrajectory. The tubular body 102 is not limited to a tubular structurehaving closed sidewalls and can be any component that defines at leastone interior path 106, including an open channel extending therethrough.The path 106 through the access port 100 may form a working channelconfigured to receive selected surgical instruments, such as awls, bonetaps, obturators, drills, guide wires, screw drivers, and/or surgicaldevices, such as implants and associated structures, implants, spacers,fusion devices, rods, tethers, bone anchors, plates, cables, fasteners(e.g., screws), and the like. As used in this document, surgicalimplements, instruments, and devices may be used interchangeably and areintended to include any surgical instruments or devices described hereinor known in the art.

The interior path 106 may be formed by the sidewall 104 (e.g., asubstantially cylindrical sidewall 104). The inner and outer surfaces116, 118 of the sidewall 104 may be smooth, rough, threaded, ribbed, orany other surface cover, which would aid in securing the access port 100in place during the procedure, to enhance the working channel, or toimprove access to the surgical site. One skilled in the art willrecognize that the tubular body 102 can have any size, shape,configuration, and number of sidewalls.

The sidewall 104 includes at least one flexible portion 140. As usedherein, flexible is intended to encompass any suitable materials withphysical properties that allow it to move, expand, stretch, or deformwhen a force is applied (e.g., the force from a surgical implement).Preferably, the material is resilient such that the material returns toor near its original shape after being expanded, stretched, or deformed.The flexible material may be able to resiliently stretch or deform inone direction, two directions, or three directions (e.g., x-, y-, and/orz- directions). For example, the flexible material may provide for athree-dimensional stretching. The flexibility of the material may allowfor an elongation in the range of about 5-50%, about 5-40%, about 5-30%,about 10-30%, about 10-40%, or about 20-30% in one or more directions(e.g., laterally).

The flexible portion 140 is situated along at least a portion of thelength L of the tubular body 102. The flexible portion 140 may beconfigured to stretch or deform, for example, to accommodate an angledtrajectory of a surgical implement. The flexible portion 140 may beconfigured to expand radially (as shown in FIG. 4B) and/or to stretchlaterally (as shown in FIG. 5B in the direction of the arrow). Theflexible nature of the flexible portion 140 allows surgical implementsinserted therethrough to be manipulated about their axes and thus allowa higher degree of movement of the surgical implements to orient themrelative to the tissue being operated upon. After stretching ordeforming under the force of the surgical implements, the flexibleportion 140 may be resilient in that the material returns to itsoriginal, pre-deformed shape.

The flexible portion 140 may extend along at least a portion of thelength L of the tubular body 102. As depicted in FIG. 3, the flexibleportion 140 may extend from the first end 110 (e.g., the insertion end)to a distance L1 along the length L of the tubular body 102. As shown inFIGS. 4A and 4B, the flexible portion 140 may extend from the second end120 (e.g., the access end) to a distance L1 along the length of thetubular body 102. For example, the flexible portion 140 may extend togreater than 50%, greater than 60%, greater than 70%, or greater than80% of the length L of the tubular body 102. The flexible portion 104may range from about 50-90%, about 50-80%, about 50-70%, about 50-60%,about 60-90%, about 60-80%, or about 60-70% of the length L of thetubular body 102. Although embodiments are depicted with the flexibleportion 140 extending from the first or second ends 110, 120,respectively, the flexible portion 140 may be located in any suitablelocation, and the access ports 100 may be oriented in any suitabledirection (e.g., either the first end 110 or the second end 120 may bethe insertion end and either the first end 110 or the second end 120 maybe the access end of the passage way).

The flexible portion 140 may encompass a portion of the outer perimeteror the entire outer perimeter along a given distance L1 of the length Lof the tubular body 102. In the embodiments shown in FIGS. 3, 4A, and4B, the flexible portion 140 surrounds the entire periphery orcircumference of the tubular body 102 along the distance L1 of thetubular body 102. In FIGS. 5A and 5B, the flexible portion 140 onlysurrounds a portion of the outer perimeter of the tubular body 102 alongthe distance L1 of the tubular body 102. For example, the flexibleportion 140 may surround about 20-80%, about 20-70%, about 20-60%, about30-80%, about 30-70%, about 30-60%, about 40-80%, about 40-70%, or about40-60% of the circumference of the tubular body 102.

The flexible portion 140 may be formed from a web, for example, of wovenmaterial. The flexible portion may also be in the form of a meshstructure 142, which is flexible or able to elongate in one or moredirections when a force is applied. In particular, the mesh structure142 may be in the form of a web, fabric, or cloth with a construction ofknitted, braided, woven, or non-woven (e.g., felt) filaments or fibersthat are interlocked in such a way to create a fabric or a fabric-likematerial. The mesh structure 142 may be formed, for example, frommonofilament or multifilament threads. The shape, form, and diameter ofthe threads are not particularly limited. For example, twisted thread,spun yarn, monofilament thread, multifilament thread, staple fiber, andwhisker may be used. The mesh structure 142 may be formed as anet-structure, such as a square, hexagonal, or network shape, forexample.

The mesh structure 142 may contain a given porosity in order toinfluence or enhance the flexibility of the material. Depending on thematerial selected, as the porosity and/or pore size increase (volumetricdensity decreases), the flexibility and deformability increase.Accordingly, a high porosity mesh structure 142 may be desired. Forexample, the mesh structure 142 may have a porosity of at least about30%, at least about 40%, at least about 50%, at least about 65%, or atleast about 75%. For example, the porosity may range from about 30-90%,about 30-80%, about 30-70%, about 30-60%, about 30-50%, about 40-90%,about 40-80%, about 40-70%, about 40-60%, about 40-50%, about 50-90%,about 50-80%, or about 50-75%. Porosity refers to the voids or porevolume of the mesh structure 142 and is the converse of the volumetricdensity, which is the amount, by volume, of fibers per unit volume ofthe mesh structure 142. Accordingly, porosity (%)=100%—volumetricdensity (%). The porosity or volumetric density may vary slightly fromregion to region of the mesh structure 142 and it is sufficient if theaverage value over the entire cross-section falls within the foregoingvalues.

The sidewall 104 also includes at least one rigid portion 130. The rigidportion 130 is a rigid or substantially rigid material, which is capableof substantially holding or retaining its shape when a force is applied.The rigid portion 130 comprises the remainder of the tubular body 102not containing the flexible portion 140. As shown in FIGS. 3, 4A, and4B, the rigid portion 130 may include a ring or annular collar 132, forexample, positioned at the first end 110 or the second end 120 of thetubular body 102. As shown in FIGS. 5A and 5B, the rigid portion 140 mayextend from the first end 110 to the second end 120 along the entirelength L of the tubular body 102. The rigid portion 140 may also includea combination of the annular collar 132 and one or more portionsextending along the length L of the tubular body 102.

The flexible portion 140 and the rigid portion 130 may bifurcate atleast a portion of the tubular body 102. For example, the tubular body102 may be bifurcated in a manner parallel to or perpendicular to alongitudinal axis 40. For example, FIGS. 3, 4A, and 4B depict accessports 100 bifurcated along a plane perpendicular to the longitudinalaxis 40, and FIGS. 5A and 5B depict access ports 100 bifurcated along aplane parallel to the longitudinal axis 40 for the distance L1.

The rigid portion 130 of the access port 100 is helpful for portinsertion and for attachment and fixation in the surgical setting. Inparticular, the rigid portion 130 of the access port 100 may include aprojection, attachment, or other mechanism for rigidly attaching oraffixing the access port 100 to a table arm, for example, for securingthe position of the access port 100 during the surgical procedure. Therigid portion 130 may include, for example, a ridge 134 along at least aportion of its circumference designed to engage a table arm.

The tubular body 102 may have any suitable cross-sectional configurationdesigned to accommodate the surgical implements, for example, on a givenangled trajectory. The tubular body 102 may have a substantially uniformdiameter along a portion of length L or its entire length L. As shown inFIG. 5A, the access port 100 can have a substantially uniform diameteralong its entire length L in its relaxed state. For example, the firstdiameter dl at the first end 110 may be equivalent to the seconddiameter d2 at the second end 120 of the access port 100 (and along theentire length L). FIG. 5B depicts access port 100 when a force isapplied to the flexible portion 140 sufficient to stretch or deform theflexible portion 140. In particular, a lateral force may be applied inthe direction of the arrow designed to allow for an angled trajectory ofone or more surgical implements. Thus, the force may alter the geometryof the access port 100 such that the first diameter d1 is now greaterthan the second diameter d2 in the expanded configuration. After theforce is removed, the flexible portion 140 may return to the relaxedstate having a uniform diameter along its length L as shown in FIG. 5A.

The tubular body 102 may have first and second diameters d1, d2, whichare not equal. For example, the first diameter d1 may be larger than thesecond diameter d2 or the second diameter d2 may be larger than thefirst diameter d1. The tubular body 102 may also have one or moreintermediate diameters (e.g., a third diameter) positioned between thefirst and second ends 110, 120. The intermediate diameter or thirddiameter may be the same or different (e.g., larger or smaller) from thefirst and second diameters d1, d2 to provide for a tubular body 102having varying widths or diameters along its length L.

The tubular body 102 may also include an enlarged portion 126 in itsrelaxed state or expanded state. As shown in FIGS. 3 and 4A, theenlarged portion 126 may include a portion of the tubular body 102proximate to the first end 110. As shown in FIG. 4B, the enlargedportion 126 may include a portion of the tubular body 102 near thesecond end 120. The enlarged portion 126 may include the flexibleportion 140 (FIGS. 3 and 4B) and/or the rigid portion 130 (FIG. 4A).Similarly, the tubular body 102 may also include one or more narrowedregions and/or transition regions, for example.

The tubular body 102 may be of any suitable size and shape designed toimprove access to the working area of the surgical site. For example,the tubular body 102 may have a shape selected from a bulbous shape, anhourglass shape, a dumbbell shape, a tapered shape, a flared shape, afunnel shape, or the like. Although depicted as a substantially tubularstructure, the access port 100 can be a variety of different shapes andsize, such as having round, square, rectangular, triangular, elliptical,or octagonal inner and/or outer perimeters. Thus, the access port 100can have any suitable cross-section and is not limited to thesubstantially cylindrical cross-sections shown in the illustrativeembodiments.

The surgical access port 100 including the flexible portion 140 and therigid portion 130 can be formed of any suitable surgical material.Preferably, the surgical access port 100 is comprised of one or morephysiologically compatible or biocompatible materials, for example, thathave the property or characteristic of not generating injury, toxicity,or immunological reaction to living tissues. Suitable physiologicallycompatible or biocompatible materials include, but are not limited toplastics, such as polyether ether ketone (PEEK); metals, such assurgical stainless steel, titanium, and other materials known in theart. The surgical access port 100 may also be made of a combination ofsuitable materials.

With regard to the flexible portion 140, malleable, bendable, orflexible materials, including metals, plastics, inorganics, andcomposites, known in the art may be used. Metals may include, forexample, titanium, titanium alloys, surgical stainless steel, nickeltitanium alloys, and shape memory alloys.

Plastics may include, for example, polyesters, such as polyethyleneterephthalate and polybutylene terephthalate; aliphatic polyesters;polyethers; polyether-esters, such as polybutester; polyamides, such asnylon and polycaprolactam; polyamines; polyimines; polyurethanes;acrylic polymers and copolymers; modacrylics; vinyl halide polymers andcopolymers, such as polyvinyl chloride; polyvinyl alcohols; polyvinylethers, such as polyvinyl methyl ether; polyvinylidene halides, such aspolyvinylidene fluoride and polyvinylidene chloride; polyacrylonitrile;polyaryletherketones; polyvinyl ketones; polyvinyl aromatics, such aspolystyrene; polyvinyl esters, such as polyvinyl acetate; copolymers ofvinyl monomers with each other and olefins, such as etheylene-methylmethacrylate copolymers, acrylonitrile-styrene copolymers, ABS resins,and ethylene-vinyl acetate copolymers; alkyd resins; polycarbonates;polyoxymethylenes; polyphosphazine; polyimides; epoxy resins; aramids,rayon; rayon-triacetate; spandex; silicones; and combinations thereof.

Inorganics may include, for example, biocompatible inorganic fibers suchas carbon fibers, graphite fibers, glass fibers, silica fibers, zirconiafibers, apatite fibers, and material fibers such as stainless steelfibers, titanium fibers, alumina fibers, boron fibers, etc. As discussedabove, these fibers may be formed into a web, fabric, cloth, or thelike.

With regard to the rigid portion 130, a biocompatible plastic, likepolyether ether ketone (PEEK), polyetherketoneketone (PEKK), ultra-highmolecular weight (UHMW) polyethylene, or other polymers and plasticsknown in the art which are physiologically compatible may be used. Abiocompatible metal, such as stainless steel, titanium, titanium alloys,surgical steel, and metal alloys may also be used, for example. Anyother materials or a combination that are physiologically compatible mayalso be used, such as bone or plastic.

According to another embodiment, a surgical access device for retractingtissue includes a retractor 200 or retractor system. Referring to FIGS.6-9, embodiments of minimally invasive retractors 200 and/or theretractor blades 202 are illustrated. The retractor 200 includes aplurality of retractor blades 202 each having a generally arcuatesegment 204 with a distal end 220 (e.g., for insertion into the surgicalsite), a proximal end 210 (e.g., for attachment to arms 230 or a frame),an inner surface 216, and an outer surface 218. The retractor blades 202are radially spaced apart to define a passage 206 extending from theproximal end 210 to the distal end 220. The outer surface 218 of all ofthe retractor blades 202 combined may form a substantially circularcross-sectional configuration. The outer surface 218 has a plurality ofspiral ridges 224 projecting therefrom configured to facilitateinsertion in a rotational manner. The retractor blades 202 are alsoconfigured to pivot away from a center line 42 such that the passage 206is expandable in response to an applied force such that the tissue inthe surgical site is retracted.

According to yet another embodiment, a method of retracting tissueincludes inserting the surgical retractor 200 into an incision in apatient's skin by rotating the surgical retractor 200 (e.g., in acorkscrew manner). After the retractor 200 is appropriately inserted,the blades 202 of the surgical retractor 200 may be moved away from acenter line 42 thereof, thereby enlarging the incision.

The retractor 200 may be in the form of a self-tapping retractor, whichenables the retractor 200 to at least partially corkscrew into anopening instead of forcing the entire retractor 200 into the surgicalopening or incision. In other words, a portion of retractor 200 (e.g.,distal end 220) may be inserted and plunged at least partially into thebiological body and then the remainder of the retractor 200 can bethreadably turned or screwed into the biological body, for example, whena torque is applied. By rotatably screwing the retractor 200 into thebiological body, insertion time and the effort required to insert theretractor 200 into the biological body can be greatly reduced. Theraised ridges 224 may contain at least one cutting edge to facilitateinsertion of the retractor blades 202 when a torque is applied.

The retractor blades 202 may include a beveled tip 228 at the distal end220 to enhance insertion of the retractor blades 200 into the surgicalsite. For example, the beveled tip 228 may be tapped into the site, forexample, with a plunge force or by using a mallet or other device whichapplies a force, e.g., non-rotational force, to the retractor blades202. After the initial insertion, the retractor blades 202 may beadvanced through rotation to control the position or depth of theretractor blades 202. The retractor blades 202 may be advanced through asleeve or cannula 236, for example, as shown in FIG. 9, where thediameter 01 the retractor blades 202 is smaller than the diameter Ø1 ofthe sleeve or cannula 236.

The retractor blades 202 may form generally curved or arcuate structures204 that cooperate to define segments of a substantially circularcross-sectional configuration. The retractor blades 202 may definesegments of a substantially c-shape, thereby providing sufficientstiffness or rigidity such that retractor blades 202 resist bending fromthe counter forces of the retracted tissues. Depending on the number ofretractor blades 202, each retractor blade 202 may have an arcuateconfiguration that is less than about 180° (e.g., two retractor blades202), less than about 120° (e.g., three retractor blades 202), less thanabout 90° (e.g., four retractor blades 202), less than about 72° (e.g.,five retractor blades 202), etc. For example, FIG. 7 depicts tworetractor blades 202 where each retractor blade 202 has an arcuateconfiguration of about 180° and FIG. 8 depicts three retractor blades202 where each retractor blade has an arcuate configuration of about120°. Although the retractor blades 202 are depicted as arcuatestructures 204, the retractor blades 202 may be of any suitable size,shape, cross-section (e.g., convex, square, rectangular), or otherconfigurations known in the art.

Before, during, or after insertion, the retractor blades 202 may be incontact with one another or may be spaced apart. As shown in FIGS. 6 and9, at least a portion of the retractor blades 202 may be in contact withone another to form a substantially closed passage 206 extending fromthe proximal end 210 to the distal end 220. As shown in FIGS. 7 and 8,the retractor blades 202 may be spaced apart from one another to definea passage 206 extending from the proximal end 210 to the distal end 220and one or more slots 206 between each of the respective blades 202. Inparticular, the retractor blades 202 may be radially spaced apart todefine one or more continuous slots 222 along a substantial portion orthe entire length of the retractor blades 202.

The outer surface 218 of the retractor blades 202 include one or moreraised ridges 224 that extend away from the outer surface 218 (i.e.,radially outward). As illustrated in FIGS. 6-9, each ridge 224 at leastpartially spirals about the center line 42 or longitudinal axis and/orextends angularly along the length of the outer surface 218 of theretractor blades 202. The raised ridges 224 may be separated by one ormore grooves 226. The ridges 224 may be straight or curved. In addition,the ridges 224 may be continuous or segmented. Preferably, the ridges224 are integral and continuous with the retractor blades 202 (i.e.,one-piece). When the blades 202 are combined or closed together, theraised ridges 224 may form a substantially helical thread along theperiphery of the outer surface 218 of the retractor blades 202. Thehelical thread may be right or left handed, for example.

As shown in FIG. 8, the ridges 224 may be pitched at an angle θ relativeto an axis substantially perpendicular to the center line 42 of theretractor blades 202. The angle θ or pitch may range from about 0 to 90degrees, 5 to 75 degrees, 5 to 45 degrees, 10 to 80 degrees, 10 to 60degrees, 15 to 50 degrees, 15 to 30 degrees, 20 to 60 degrees, 30 to 50degrees, or 45 to 90 degrees, and all sub-ranges therebetween. Forexample, the angle θ or pitch of the ridges 224 may be approximately 0,10, 20, 30, 40, 50, 60, 70, 80, or 90 degrees, or any other angle θ orpitch as would be suitable to rotatably insert the retractor blades 202.The shape or angle θ of the ridges 224 may be selected to facilitateinsertion of the retractor blades 202 without damaging the integrity ofthe surrounding tissue.

Each ridge 224 may have the same height, width, length, and angle θ orpitch relative to one another. In certain embodiments, the ridges 224may vary from other ridges 224 with respect to height, width, length,and/or angle θ or pitch. In some embodiments, the height, width, andangle θ or pitch may be constant or variable along each ridge 224. Allof these parameters of ridges 224 may impact torsion, penetration,retractor effectiveness, and/or other parameters.

The ridges 224 may extend along the entire length of the retractorblades 202 or only a portion of the length of the retractor blades 202.In particular, the retractor blades 200 may be fully threaded such thatthe spiral ridges 224 extend from the distal end 220 to the proximal end210. In the alternative, the retractor blades 202 may be partiallythreaded such that the spiral ridges 224 extend from the distal end 220to a distance less than the proximal end 210. In certain embodiments,the length of the ridges 224 may extend from about 1-100 percent, 1-50percent, 50-100 percent, 25-50 percent, 50-75 percent, 5-40 percent,10-30 percent, and all sub-ranges therebetween, of the length of theretractor blades 202. For example, the ridges 224 may extend about 10,20, 30, 40, 50, 60, 70, 80, 90, or 100 percent, or any other percent ofthe length of the retractor blades 202.

The number of ridges 224 on the outer surface 218 may be of any suitableamount or quantity. For example, larger retractor blades 202 and/orcloser ridges 223 with smaller grooves 226 positioned therebetween mayallow for a greater number of ridges 224, and conversely, smallerretractor blades 202 and/or further spaced apart ridges 223 with largergrooves 226 may allow for a smaller number of ridges 224. Depending onthe size and shape of the retractor blades 202 and the ridges 224, thenumber of ridges 224 may range, for example, from about 1-200, about1-50, about 1-10, about 1-5, and all sub-ranges therebetween. It will beunderstood that when the arcuate segments 204 are combined together, theridges 224 may appear as one continuous spiral (e.g., FIG. 6).

The retractor blades 202 may be attached or affixed to any suitable arms230, handles, frames, devices, or the like known in the art. As shown inFIG. 7, the proximal end 210 of each of the retractor blades 202 may beaffixed to the distal end 232 of one or more arms 230. The arm 230includes a proximal end 234 which may be affixed to another device ormechanism or may include a handle (not shown) such that an operator isable to maneuver the retractor blades 202. The retractor blades 202 maybe mounted to a retractor frame, for example, as exemplified in U.S.Pat. No. 8,353,826, which is hereby incorporated by reference in itsentirety for all purposes. The retractor 200 may further include one ormore hinges, cranks, or the like (not shown), and/or may be configuredto engage a variety of different tools, such as wrenches orscrewdrivers, to facilitate the desired movement of the retractor blades202.

After the retractor blades 202 have been inserted into the surgicalspace, for example, by threadably turning or rotatably screwing theretractor 200, the passage 206 and the slots 222 are expandable in orderto retract and expose the patient's tissue. In particular, the retractorblades 202 may move or pivot away from the center line 42 in response toone or more applied forces. For example, the retractor blades 202 maypivot at a hinge (not shown) in response to manual forces applied by thesurgeon. The retractor blades 202 may pivot away from the center line 42(i.e., radially outwards) in order to create a larger opening throughthe passage 206 and act to retract the surrounding tissue at theselected surgical site. The movement of the retractor blades 202 mayinclude polyaxial motion, for example, to allow the retractor 200 toexpand medial-laterally, cephalad-caudally, or both. Surgeon preferencewill dictate the need for one or more stages of dilators or scalpelblades to aid in expanding the wound before introducing the retractor200. Normal surgical techniques may also be used to close any incisions.

The retractors 200 including the retractor blades 202 may be formed fromany suitable materials known in the art and may include any of thematerials discussed for the access ports 100. In addition, the accessdevices described herein may be sterilized by any suitable methodsincluding, but not limited to, autoclaving, ethylene oxide, radiation,cold sterilization (e.g., hydrogen peroxide plasma), immersionsterilization, or a combination thereof.

The access devices may serve a number of different functions, forexample, including aiding insertion of surgical devices and implements(e.g., implants, screws, and the like), providing for soft tissuedistraction, enhancing penetration and advancement of the access deviceinto the surgical site, allowing for fixation and attachment to a tablearm, and other similar functions. The access devices are adapted topermit insertion through minimally invasive procedures, and areespecially suitable for spinal surgeries and procedures. By way ofexample, the spinal surgeries may include, but are not limited to,insertion of vertebral fusion and fixation devices, including rods,plates, cables, bone anchors, fasteners, such as screws, and the like,or any procedure requiring surgical access to a patient.

Although the invention has been described in detail and with referenceto specific embodiments, it will be apparent to one skilled in the artthat various changes and modifications can be made without departingfrom the spirit and scope of the invention. Thus, it is intended thatthe invention covers the modifications and variations of this inventionprovided they come within the scope of the appended claims and theirequivalents. It is expressly intended, for example, that all rangesbroadly recited in this document include within their scope all narrowerranges which fall within the broader ranges. It is also intended thatthe components of the various devices disclosed above may be combined ormodified in any suitable configuration.

What is claimed is:
 1. A surgical access device for retracting tissuecomprising: a plurality of retractor blades each having a generallyarcuate segment with a distal end, a proximal end, and an outer surface,the plurality of retractor blades are radially spaced apart to define apassage extending from the proximal end to the distal end, the outersurface of the plurality of retractor blades forming a substantiallycircular cross-sectional configuration having a plurality of spiralridges projecting therefrom, wherein the at least one retractor blade isconfigured to pivot away from a center line such that the passage isexpandable in response to an applied force.
 2. The device of claim 1,wherein the plurality of retractor blades are fully threaded such thatthe plurality of spiral ridges extend from the distal end to theproximal end.
 3. The device of claim 1, wherein the plurality ofretractor blades are partially threaded such that the plurality ofspiral ridges extend from the distal end to a distance less than theproximal end.
 4. The device of claim 1, wherein the plurality ofretractor blades are self-tapping.
 5. The device of claim 4, wherein theplurality of retractor blades have a beveled tip at the distal end. 6.The device of claim 1, wherein the plurality of retractor blades may beadvance through a cannula.
 7. The device of claim 1, wherein theplurality of ridges is separated by one or more grooves.
 8. The deviceof claim 7, wherein the plurality of ridges are straight.
 9. The deviceof claim 7, wherein the plurality of ridges are curved.
 10. The deviceof claim 7, wherein the plurality of ridges form a helical thread aroundthe outer surface.
 11. A method of retracting tissue comprising:inserting a surgical retractor into an incision in a patient's skin byrotating the surgical retractor; and moving the at least one blade ofthe surgical retractor away from a center line thereof, therebyenlarging the incision wherein the surgical retractor comprises: aplurality of retractor blades each having a generally arcuate segmentwith a distal end, a proximal end, and an outer surface, the pluralityof retractor blades are radially spaced apart to define a passageextending from the proximal end to the distal end, the outer surface ofthe plurality of retractor blades forming a substantially circularcross-sectional configuration having a plurality of spiral ridgesprojecting therefrom, wherein the at least one retractor blade isconfigured to pivot away from a center line such that the passage isexpandable in response to an applied force.
 12. The method of claim 11,wherein the plurality of retractor blades are fully threaded such thatthe plurality of spiral ridges extend from the distal end to theproximal end.
 13. The method of claim 11, wherein the plurality ofretractor blades are partially threaded such that the plurality ofspiral ridges extend from the distal end to a distance less than theproximal end.
 14. The method of claim 11, wherein the plurality ofretractor blades are self-tapping.
 15. The method of claim 14, whereinthe plurality of retractor blades have a beveled tip at the distal end.16. The method of claim 11, wherein the plurality of retractor bladesmay be advance through a cannula.
 17. The method of claim 11, whereinthe plurality of ridges is separated by one or more grooves.
 18. Themethod of claim 17, wherein the plurality of ridges are straight. 19.The method of claim 17, wherein the plurality of ridges are curved. 20.The method of claim 17, wherein the plurality of ridges form a helicalthread around the outer surface.